The present invention relates to the production of cement and, more specifically, to a raw mixture for the production of a high-alumina refractory cement adapted to be used in the manufacture of refractories.
Known in the art is a raw mixture for the production of a refractory aluminous cement containing lime and an aluminous component.
To produce cement from this mixture, the latter is subjected to calcination at a temperature within the range of from 1,500.degree. to 1,550.degree. C., which is associated with considerable power consumption and the necessity of using calcination furnaces provided with a high-refractory lining.
Also known in the art is a raw mixture for the production of a refractory aluminous cement which incorporates a commercial alumina, calcium oxide and minor amounts of silica and iron oxide, the components being taken in the following proportions, percent by mass:
Commercial alumina: 72 to 75 PA0 Calcium oxide: 22 to 25 PA0 silica and iron oxide: below 2 PA0 aluminous component (calculated for Al.sub.2 O.sub.3): 69 to 73 PA0 calcareous component (calculated for CaO): 11 to 23 PA0 chlorides of said metals: 20 to 4.
This raw mixture enables the production of a high-alumina refractory cement with a predominant content of calcium dialuminate ensuring the cement refractoriness up to 1,760.degree. C.
Refractory cements based on this mixture are produced by calcination of the latter at a temperature within the range of from 1,500.degree. to 1,550.degree. C. in rotating furnaces which is also associated with considerable heat consumption and an accelerated wear of the refractory lining.